Circuit breaker



May 7, 1940. ,J FREESE 2,199,626

CIRCUIT BREAKER I Filed Oct. 21, 1936 2 Sheets-Sheet 2 I I H gem/dff'eefe. I v q% R TW- Patented May 7,1940

UNITED STATES PATENT OFFICE CIRCUIT BREAKER Gerald J. Freese, Edgewood, Pa., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application October 21, 1936, Serial No. 106,809 1'7 Claims. (0]. 175-298) My invention relates to electrical devices in general and more particularly to terminal connectors for electrical devices; v

The principal field for immediate application of the invention is' in connection with electrical circuit controlling devices such as switches or circuit breakers or the like for controlling lighting and distribution feeder circuits and I shall hereinafter describe several embodiments of my invention in connection with such devices without, however, in any way intending to restrict the application or scope of my invention except as indicated by the appended claims.

There are a number of specific applications for circuit breakers and switches, each of which requires a different type of connection of. the device in its circuit. The four main types of connections are briefly as follows: the front or top connection for industrial applications involving lower current ratings in which the circuit conductor is clamped by a terminal screw to the top of the terminal of the device; the end connection for industrial applications involving higher current ratingsin which a separate terminal lug provided with an end opening to receive the circuit conductor is clamped to the main terminal by a terminal screw, the conductor being secured in the lug opening by soldering or other means; the switchboard connection in which the terminal of the device is provided with an opening to re-' ceive a switchboard stud from the rear of the device; and the lighting panelboard or power panel connection in which the terminal is connected by means of a screw to a power panel bus or bus strap located at the rear of the device. In view of the several different types of connections mentioned above, it has heretofore been necessary for the purchaser of such devices to specify the particular use or type of connection required so that the manufacturer could equip the device with the proper form of terminal means to adapt the device to the use specified. It is, accordingly, one object of my invention to provide a circuit controlling device with im-' provedterminal' connectors whereby the device may be removably connected to its circuit by any.

one of the four different main types of connections mentioned above.

Another object of my invention is to provide an improved terminal structure and mounting therefor for connecting an electrical device inan external circuit.

Another object of my invention is to provide an electrical device .with an improved terminal structure adapting the same for a plurality of diiferent types of solderless removable connections to an external circuit.

Since my invention is not concerned particularly with the operating mechanisms or structural features of the circuit controlling device proper, I have limited the showing of the preferred embodiments of the invention to those parts of the device to which my invention is especially applicable.

The novel features that I considercharacteristic of my invention are set forth in particular in the appended claims. The invention itself, however, both as to structure and operation together with additional objects and advantages thereof. will best be understood from the following detailed description of. specific embodiments thereof when read in connection with the accompanying drawings, in which:

Figure 1 is a vertical sectional view of a portionof an electrical circuit controlling device showing my improved terminal means applied thereto and illustrating an end type of electrical connection of the device to a circuit,

Fig. 2 is an end elevational view of the portion of the circuit controlling device shown in Fig. 1, illustrating certain details of my improved ter minal meansand the manner of mounting the same,

Fig. 3 is a vertical sectional view similar to Fig. 1 illustrating a rear type of connection of the terminal means of. the device to a bus of a lighting panelboard or power panel,

Fig. 4 is a vertical sectional view similar to Fig. 1 illustrating a rear type of connection of the terminal means of the device to a switchboard stud,

Fig. 5 is a vertical sectional view of a portion means suitable for use with lower current values illustrating a top' type of electrical connection, I,

Fig. 6 is an exploded view of the conducting strip and the terminal means illustrated in Fig. 1,

Fig. '-'I is a vertical sectional view of. a portion of a circuit controlling device similar to Fig. 1 showing a modified form of terminal structure embodied therein, I

Fig. 8 is an end elevational view of the portion of the circuit. controlling device shown in Fig. '7; and,

Fig. 9 is a sectional view of a lighting panelboard showing a. plurality of circuit breakers embodying my improved terminal connectors mounted therein and connected tothe busses and load conductors thereof.

The electrical device itself may be in the form of. a switch, a circuit breaker or any other type of electrical device that may require a number of different types of electrical connections in difierent applications.

Referring to the drawings, one end portion of a circuit breaker is illustrated generally at 9. The base H of the circuit breaker is of vmolded insulating material and has ,mounted thereon bolts l1. pass through aligned openings I9 provided at each end of the cover and base and have threaded end portions for providing a means for securing the breaker to any suitable form of support or for clamping the cover and base toather.

In the application of the' circuit breaker or device to circuits in which the maximum value of the normal current does not exceed 25 or 35 amperes, the form of my improved terminal means illustrated in Fig. 5 provides a satisfactory terminal structure. This form of terminal means has provision for removably connecting the circuit breaker to a circuit by any one of three of the main types of connections mentioned above.

Referring to Fig. 5, this form of terminal means comprises a member or insert 2| of conducting material, a terminal strip 23 and a terminal screw 45 also of conducting material. The member or insert 2| has a rectangular. body portion 21 and a reduced portion 23 of circular cross section. The insert 2| is adapted to be positioned in a square recess 3| provided in the base of the circuit breaker which opens into a chamber 33 formed in the base adjacent the lower corner thereof. The base II is also provided with an arched recess 35 at the end thereof, which joins the square recess 3|. The reduced portion 23 of the insert is received in a circular opening 31 formed in the top portion of the base The conductor strip 23 has a stationary contact secured to one end thereof in any suitable manner, as for example by soldering or welding and is shaped to conform with the shape of the inner surface of the base structure U so as to lie flat against the same. The, other end of the terminal strip 23 has an opening 33 formed therein for receiving a further reduced portion 4| (see Fig. 6) formed integral with the top of the reduced por tion 29 of the insert 2|. Thecorners of the end of the terminal strip 23 are bent upwardly, as indicated in Fig. 5. The insert 2| is positioned in the square recess 3| by insertion through the chamber portion 33 or the base II and its reduced portion passes through the circular opening 31.

A vertical threaded opening 43 extends through the squared body portion 21 and the reduced portions 29 and. The reduced portion 4| passes through the opening 33 provided in the terminal strip 23 and has its edges spun over against the same, so that the insert 21 is rigidly held in its position in the base The spun over reduced portion 4|, together with the shoulder formed by the reduced portion 23 engaging the cooperating shoulder formed by the edge of the opening 31 on the base ll, holds the terminal strip 23 securely in engagement with the inner surface of the base A terminal screw 45 is threaded into the opening 43 for the purpose of clamping a conductor wire 41 to the terminal strip 23. v The conductor 41 passes between the up-turned corners of the terminal strip 23 and is wrapped around the body of the terminal screw 45. A washer 43 may be positioned between the conductor wire 41 and the head of the terminal screw 45, so as to provide a more emcient clamping connection. The terminal means described above may also be used to connect the circuit breaker to a switchboard stud or to a power panel bus.

In connecting the breaker equipped with this form of terminal means to a switchboard stud, the terminal screw 45 is removed and the switchboard stud, not shown, passes through the threaded opening 43 and is provided with a nut adjacent the free end thereof for clamping the terminal means and breaker base to the insulating panel of the switchboard in a manner similar to the connection shown in Fig. 4. The terminal means is adapted to be connected to a bus strap of a lighting panelboard or power panel bus by removing the terminal screw 45 and inserting a bus bar screw of reduced diameter, which passes through the opening 43 and threadedly engages an opening in the bus strap in a manner similar to that shown in Fig. 3.

It will thus be seen that the above described form of my improved terminal means has provision for three diiferent types of electrical connections oi the same to an external circuit.

In applications of the circuit breaker or device to circuits having normal current values of more than 25 or 35 amperes, the form of terminal means illustrated in Figs. 1, 2, 3, 4 and 6 is used. This form of terminal means may also be used in connection with circuits carrying lower cur-- rent values, if desired. The form of terminal means illustrated in Figs. 1, 2, 3, 4 and 6 is substantlally similar to the terminal means illustrated in Fig. 5 and described in connection therewith, except that the squared body portion of the insert is provided with a transverse opening 3| which passes through the same and joins the internally threaded vertical opening 43. Since the structure of this form of terminal means is substantially identical in most respects to the form shown in Fig. 5, the same reference characters have been used wherever applicable. The structure of the circuit breaker base for accom- .modatlng the terminal means is identical with .a reduced portion 23 and a further reduced portion 4|. The insert is provided with a vertically disposed threaded opening 43 which passes through the squared body portion and the reduced portions 23 and 4| and joins a transverse opening 3!. The insert is positioned inits recess by insertion through the chamber 33, the upper reduced portion thereof passes through an opening 33 provided in the terminal strip 23 and has its edge spun over against the same to securely serted in the transverse opening 5|.

clamp the insert in position in its recess and the terminal strip against the inner surface of the base I l in the same manner as described in connection with first form-of terminal means. A terminal screw 'is threaded into the upper end of the threaded opening 43 and a second fiat headed screw 53 is threaded into the lower end of the opening.

The last described form of terminal means provides a means for removably connecting the circuit breaker or device to its circuit by any one of the four main types of connections without necessitating the use of lugs, additional binding screws or solder as will now be described.

In industrial applications of the breaker involving higher values of current, the conductor is connected to the terminal means in the manner illustrated in Fig. 1. In this case the terminal screw 45 is loosened and the conductor is in- The screw 45 is then tightened against the conductor 55 and functions to securely clamp the same in the opening 5| with a lock nut effect. The screw 53 acts as a filler to fill the lower portion of the vertical opening up to the surface of the transverse opening. If desired, the surface of the end of the lower screw 53 may be roughened to provide for a biting engagement with the conductor wire.

When the breaker is to be connected to a bus of a lighting or power panelboard,'the screws 45 and 53 are removed and an elongated screw 51 (see Fig. 3) is inserted in the opening 43. The elongated screw 51 is of smaller diameter than the screws 45 and 53 and is adapted to pass through the vertical threaded opening 43 and threadedly engage a threaded opening in a bus strap 59, as shown in Fig. 3. The bus strap 58 is secured to the bus Si by means of a screw 63 which passes through a washer 64 and an opening provided in the bus strap 59 and engages a threaded opening in the bus 6|. The breaker base and cover are adapted to be mounted on the bus pan 6'! of the panelboard, by means of the threaded bolts H which pass through the breaker cover and base II and engage threaded openings provided in the bus pan Bl. Insulating spacer sleeves 69 surround the lower portions of the threaded bolts I'I. In the lighting or power panelboard type 0 connection the switches or circuit breakers are adapted to be mounted side by side in a plurality of rows in the panel box in the manner illustrated in Fig. 9. The panel box 58 contains a mounting pan 61 spaced from the bottom or rear wall of the box by insulating strips 50 and secured to the wall by a plurality of screws 62. A plurality of conductor busses 61 are mounted on transverse insulating strips 66 (only one being shown). The busses 6| are centrally disposed in the panel box and extend parallel to one another. The circuit breakers 9 are mounted in rows in the box by means (i their mounting bolts H which pass through the casings of the circuit breakers and through the spacer sleeves 69 and engage in threaded openings in the bus pan 61 and in angle irons 68 mounted on the edges of the pan. The end portions of the circuit breakers of one row are disposed transversely above one of the busses 6|, while the end portions of another row of the breakers are likewise transversely disposed abdve' another one of the busses iii. The line terminal of each breaker is thus located above a bus and isadapted to be connected to the same in the manner illustrated in Figs. 3 and 9.

It will be noted that the mounting means and terminal connectors of the circuit breakers are such as to permit ready mounting and connection of the same or removal thereof from the open side of the panel box. The load conductors 10 of the panelboard are electrically connected to the load terminal connectors of the circuit breakers 9 by insertion in the transverse openings of the inserts in the manner illustrated in Fig. 1. Straps 12 may be mounted at intervals along the center bus 6| for connecting the same to certain of the breakers or certain of the poles thereof if multipole breakers are involved. A cover plate 14 is removably mounted on the open side of the panel box 58 by means of screws 16.

Where the circuit breaker is to be used in connection with a switchboard, the electrical connections are effected in a manner illustrated in Fig. 4. The breaker base ll rests uponthe insulating panel H of the switchboard.- A switchboard stud 13 passes through the panel H and has a reduced portion 15 of smaller diameter than that of the internally threaded opening 43 which passes upwardly therethrough. A nut 11 is threaded on the upper threaded end of the switchboard stud 13 and serves to electrically connect the same to the terminal strip 23, and also to securely clamp the base in engagement with the insulating panel H in cooperation with an insulating spacer I9 and a nut 81 mounted on the stud I3 beneath the panel. The switchboard stud passes through an opening provided in a bus bar 83 and is electrically connected to the same by means of a pair of nuts 85. The other terminal of the circuit breaker is connected to a second switchboard stud in the same manner as previously described.

The form of terminal connector shown in Figs.

and 4. This form of terminal and the manner of mounting the same are identical in all respects to the form illustrated in Figs. 1 through 4 except that the transverse opening in the insert is substantially rectangular in shape instead of circular to accommodate a copper clamping shoe 81. The shoe 8'! is of a width slightly less than that of the transverse opening and of a length equal to that of the opening. The under surface of the shoe may be hollowed out as indicated in Fig. 8 to fit a conductor wire, and the surface of the hollowed out portion may be roughened to more firmly clamp'the conductor wire. The bottom of the square transverse opening may also be hollowed out to provide a trough to receive the conductor wire. A special screw 89 is provided with a pin 9| which passes through an opening in the shoe 81. The end of he pin is fringed and pressed over against theiedges of the opening'in order to provide a removable pivotal coupling between nect the device in its circuit by any one of the.

disposed in said transverse opening,

previously described types of connections by removing the screw 89 and-the shoe 81. The removal of the shoe is readily eflected by fully unscrewing the screw 89 which causes the fringed ends to be pulled through the opening in the shoe.

While several forms of terminal means have been described in connection with a single pole circuit breaker, it is obvious that they are equally applicable to multipole circuit breakers and other forms of electrical devices.

It will thus be seen that a circuit controlling device equipped with my improved terminal means has provision for any one of three or more diflerent types of electrical connections of the device to an external circuit depending on which form is used, without necessitating the use oi terminal lugs, additional binding screws or solder, thus greatly facilitating installation of the device.

While in accordance with the patent statutes I have disclosed several embodiments oi my invention, the principles herein involved are applicable to other structures, and I desire, therefore, that the language of the accompanying claims shall be accorded the broadest reasonable construction and that my invention be limited only by what is explicitly stated in the claims and by the prior art.

I claim as my invention:

1. In an electrical device the combination of a base for supporting said device and terminal means for removably connecting said device in a circuit, said terminal means comprising a terminal strip and a member of conducting material secured to said strip having a vertically threaded opening extending therethrough and a transverse opening extending through a side of said member and joining said vertical opening, a clamping shoe disposed in said opening, and a terminal screw threaded in said vertical opening and removably coupled to said shoe.

2. In a circuit controlling device, a base provided with recesses adjacent the ends thereof, terminal means secured in said recesses for removably connecting said device in a circuit, said' terminal means each comprising a member of conducting material provided with a vertical internally threaded opening and a transverse opening joining the vertical opening, both openings extending through said member, a clamping shoe a screw threaded in said vertical opening and means'tor removably and pivotally coupling said shoe to the end of said screw.

3. In a circuit breaker panelboard, a bus and a plurality oi circuit breakers each having a base of insulating material, terminal means for connecting each breaker in a circuit of the panelboard, comprising a pair 0! identical metallic inserts secured in recesses provided in said base, each of said inserts having an internally threaded opening extending therethrough perpendicular to the base and a transverse opening joining the first said opening and extending through a side of the insert, an elongated screw extending through the first said opening of one of said inserts of each breaker for engaging said bus and a terminal a screw threaded in the first said opening of the other of said inserts 01 each breakerior clamping a load conductor of the paneiboard in the transverse opening oi said last mentioned insert.

4. In an electrical device, a base. terminal means supported by the base for providing a plurality of types of removable electrical connections of said device to an electrical circuit, said means comprisinga member of conducting material having a vertical threaded opening extending therethrough and a horizontal opening Joining said vertical opening and extending through a side of said member, said vertical opening being adapted to receive a terminal screw to clamp a conductor in said horizontal opening for one of said types of connections, and for receiving an elongated screw of reduced diameter upon removal ot'the terminal screw, adapted to pass through said member and engage a bus connection for a second type of connection, and for receiving a threaded conducting stud of a switchboard upon removal of the aforementioned screws for a third type of connection; and means independent of the openings, screws and stud for securing said'member to the base.

5. In an electrical circuit controlling device, the combination of circuit controlling mechanism, a base of insulating material for supporting said mechanism, terminal means supported by the base for providing a plurality of diflerent types of electrical connections of said device to an electric circuit, said means comprising a member of conducting material having a vertical threaded opening extending therethrough and a horizontal opening Joining said vertical opening and extending through a side of the member, said vertical opening being adapted to receive a terminal screw for clamping a conductor inserted in said horizontal opening for one type of connection, and adapted to receive an elongated screw upon removal of the terminal screw, for passing through said opening and engaging a bus connection for a second type of connection, and for receiving a threaded conducting stud of a switchboard upon removal of the aforementioned screws for a third type oi connection; and means independent of said openings and screws for securing said memher to said base.

6. In an electrical device, a base of insulating material having recesses formed therein, terminal means in said recesses for providing a plurality of different types of removable electrical connections of said device to an electric circuit, said terminal means each comprising a member of conducting material having a vertical threaded opening extending therethrough and a horizontal opening joining said vertical opening and extending through a side of the member, said vertical opening being adapted to receive a terminal screw i'or clamping a' conductor in said .horizontal opening for one type of connection, and adapted to I receive a headed elongated screw in place of the terminal screw, which passes through the vertical opening'for engaging a bus connection for a second'type of connection, and adapted to receive a threaded conducting stud of a switchboard in 4 place of the aforementioned screws for a third type oi'connection, and means independent oi the threaded opening, and the screws or studs for clamping said members in the recesses in said base.

7. In an electrical device, a base of insulating material having a recess thereinand a vertical opening extending through the base into the recess, a terminal insert disposed in the recess having a reduced portion extending through the opening forming a shoulder-tor engaging the lower edges of the opening, a conducting terminal strip on the base for connecting the device to the insert, said strip having an opening for receiving the end of the reduced portion of the insert, means securing the strip to the reduced portion of the insert so as to clamp the insert to the base with its shoulder against the edges of the opening in the base, and the conducting strip to the base, said insert having a vertical opening for accommodating means for connecting the insert to an electric circuit.

8. In an electrical device, a base of insulating material having a recess in its underside and a vertical opening extending through the base into the recess, a terminal member of conducting material disposed in the recess having a reduced portion extending through the opening to form a shoulder for engaging the lower edge of the opening, a conducting terminal strip on the base for connecting the device to the terminal member, said strip having an opening for the reduced portion of the member, means for securing the strip to the reduced portion of the member to clamp the member in the recess and the strip against the base, said member having a horizontal opening, a vertical threaded opening extending from the horizontal opening through the top of the member and an aligned vertical opening extending from the horizontal opening through the bottom of the member, said openings being adapted to receive connecting means for connecting the device to an electric circuit.

9. In an electrical circuit controlling device, a base of insulating material having a recess in its underside opening through the bottom and end of the base, and an opening through the base from the recess through the top of the base, a terminal member disposed in the, recess having a reduced portion extending up through the opening forming a shoulder for engaging the lower edges of the opening, a terminal strip on the base for connecting the device to said terminal member said strip having an opening for the upper end of the reduced portion, means securing said strip to the reduced portion so as to clamp said member with its shoulder against the lower edge of the opening and the strip against the base, said terminal member having a vertical'threaded opening extending therethrough and a horizontal opening joining the vertical opening and extending through the side of the member, said openings adapting the terminal member for end, bus strap, or switchboard type of electrical connection to an electric circuit.

10. In an electrical device, a base of insulating material having a shouldered opening, a terminal meansdisposed in said opening for connecting the device to an electric circuit, said terminal means comprising a member of conducting material having a vertical threaded opening extending therethrough for receiving means for connecting the device to an external circuit, said member having a shoulder for cooperating with the shoulder formed in the opening, and means including said shoulders and independent of saidthreaded opening and connecting means for clamping said mem- ,ber in its opening in the base.

11. In an electrical device, a base, a terminal through which the device may be connected in an electrical circuit. said terminal comprising means of conducting materialhaving a threaded vertical opening extending thereinto from the top, a threaded vertical opening extending thereinto from the bottom and connecting with said top opening and a horizontal opening extending into said top opening, and means securing said terminal to the base without preventing the insertion of a conductor into any of said openings.

12. In an electrical device, a base having an opening extending therethrough, aterminal disposed in said opening for detachably connecting said device to an electrical circuit, said terminal having a shoulder engaging the edge of said opening on one side of said base and a reduced portion extending through said opening, a conducting terminal stripon the opposite side of said base having an opening for receiving'the reduced portion of said terminal, the end of said reduced portion being spun over against said terminal strip to connect said strip to the. terminal and to hold said'terminal in said opening and said strip against the base, said terminal having an opening for receiving a means for connecting the terminal to an electric circuit.

13. A solderless terminal comprising a single member of conducting material having a transverse opening for receiving a conductor and a vertical threaded opening joining said transverse opening and extending clear through said member, a clamping shoe disposed in' said transverse opening for clamping a conductor therein and a screw in said vertical opening removably coupled at its inner end to said shoe, said member having means for securing the same to a base.

14. A solderless terminal comprising a single member of conducting material having a trans-- verse opening for receiving a conductor, and a vertical threaded opening joining said transverse opening and extending clear through said member, a clamping shoe in said transverse opening for clamping the conductor therein and a screw in said vertical opening having its lower end rotatably coupled to said shoe, the bottom wall of said transverse opening and said shoe being curved to conform to saidconductor, said memher having means for securing the same to a base.

15. In a panelboard, a bus and one or more electrical devices each having a base of insulating material and terminal means secured in recesses provided therefor in the base for detachably connecting said device in a circuit of the panelboard, said terminal means each having a threaded opening extending therethrough perpendicular to .the base and a transverse opening joining the first said opening and extending through a side of the terminal, an elongated screw in the first said opening of one of the terminals of each device engaging said bus, and a terminal screw in the first said opening of the other terminal of each device for clamping a load conductor of the panelboard in the transverse opening of said last-mentioned terminal.

16. In a panelboard, a bus and one or more electrical devices each having a base ofinsulating material and terminal means secured in openings provided therefor in the base, which extend through the base, for detachably connecting said device in a circuit of the panelboard, said terminal means each having a threaded opening extending therethrough perpendicular to the base and a transverse opening joining the first said opening and extending through a side of the terminal, an elongated screw in the first said opening of one of the terminals of each device engaging said bus, and a terminal screw in the first said opening of the other terminal of each device for clamping a load conductor of the panelboard in the transverse opening of said last-mentioned terminal, and means independent of the openings in said terminals and said screws for securing said terminals in the openings in said base.

17. In an electrical device, a base having an opening therein, a terminal, disposed in said opening for detachably connecting said device to an electrical circuit, said terminal having a. portion extending through said opening, and carry- 6 2,19ae2e for engaging said base at one end of said opening, a conducting terminal strip on said base at the other end of said opening, said strip having an opening for receiving the portion 01' said terminal which extends through the opening, the end of said last-mentioned portion of said terminal being pressed over against said terminal strip to connect said strip to said terminal and to hold said terminal in said opening and said strip against the base, said terminal having a vertical threaded opening extending through the outer end thereof for receiving a connecting t S crew GERALD J. FREESE. 

